The present invention relates to novel phenazine compounds. More particularly, the present invention relates to novel phenazines represented by general formula (I): ##STR2## wherein R represents a hydrogen atom, an unsubstituted or substituted lower alkanoyl group, or an unsubstituted or substituted arylcarbonyl group (hereinafter referred to as Compound (I)), a process for the production thereof and a pharmaceutical composition containing the compound.
Compounds having excellent pharmacological activities are always in demand and for this purpose, substances produced by a microorganism separated from the soil (hereinafter referred to as DO-86 strain) have been investigated. As a result, it has been found that compounds represented by general formula (I-a): ##STR3## wherein R' represents a hydrogen atom (hereinafter the compound is referred to as DC-86-Y) or COCH.sub.2 OH (hereinafter the compound is referred to as DC-86-M) are produced and these compounds possess antibacterial and anti-tumor activities. As a result of further investigations, it has been found that phenazine compounds having more excellent antibacterial and anti-tumor activities can be prepared from DC-86-Y.